/Engine/Source/Runtime/Engine/Public/GPUSkinVertexFactory.h
Set vertex attributes and SRVs to be used. The vertex declaration is made by accumulating attributes set here along with all that already been added by previous calls to this function. If any attributes are being added for the first time then we pay the cost to recreate the vertex declaration here. The SRVs are cached per attribute. If any passed in SRV is changed from the cached value then we recreate the vertex factory uniform buffer here. Note that on platforms that support manual vertex fetch, only Position will be in the final vertex stream and other attributes will be read through an SRV.
void SetVertexAttributes ( [FGPUBaseSkinVertexFactory](API\Runtime\Engine\FGPUBaseSkinVertexFactory) const * InSourceVertexFactory, [FAddVertexAttributeDesc](API\Runtime\Engine\FGPUSkinPassthroughVertexFactory\FAddVertexAttributeDesc) const & InDesc )